EP1099889B1 - Control assembly and vehicle - Google Patents

Description

The invention relates to a control device having a selector device which can be connected to a power source via a switchable line and which has at least one first position and one second position, and an area-selectable valve which can be electrically actuated by the selector device and provides at least a first and a second operating range the first operating range is a low speed range and the second operating range is a high speed range of a transmission.

Utility vehicles, such as skid steer loaders, often include hydraulically driven transmissions having a high speed and a low speed operating range. The speed range is determined by means of valves provided on the transmissions, the solenoid of which is controlled by speed control devices, which may for example be provided on an instrument panel, so that an operator can select the respective speed range. If the utility vehicle is turned off when the speed control device is in its high speed position, the vehicle will operate in its high speed operation after a restart unless the speed control device is manually brought into its low speed position by an operator. Such a vehicle is shown, for example, in US-A-5,894,899.

EP-A2-0 497 197 shows an ignition and control circuit for a vehicle which optionally allows manual starting of an internal combustion engine when the battery has failed or is absent. Starting the engine via the battery or a manual starting device is only possible when the relay is energized and there are no operating conditions of the vehicle.

The problem underlying the invention is seen in the fact that such speed selection or selection devices are often left unintentionally in their high speed position by an operator at a start of work or a recording operation and it may come to a surprising for the operator operating / working behavior.

This problem is inventively solved by the teaching of claims 1 and 6, wherein in the other claims, the solution are listed in an advantageous manner developing features.

In this way, a controller is provided which ensures a certain operating range after connection of the area selector to the power source, for example, by operation of an ignition switch or an activator, and thus the second transmission operating state at startup not accidentally or unintentionally activated. Such a control device has an area selection device and a control relay, which can be connected to a power source via a switchable line. The range selector has an input connected to the switchable line via the control relay. An output of the selector is connected to an electrically actuatable range selector valve which controls the operating range of the vehicle. The position of the range selector valve is dependent both on the position of the selector and on the state of the control relay. The control relay is deactivated when the switchable line is turned off and not energized, and only changes to an activated state to select a second operating state or high-speed region if the selector is previously in its first position after the switchable line is turned off or brought into this. If the selection device is in its second position when the switchable line becomes energized, the control relay remains deactivated until the selection device is brought into its first position. Thereafter, changing the selector from its first position to its second position with energized, switchable line and activated control relay activates the electrically actuatable range selector valve, for example, to bring a transmission into the second transmission mode or high speed range.

A system having a selector and a control relay may also be used with a variable flow hydraulic system which provides hydraulic pressure for additional vehicle driven attachments. A selection device, for example designed in the manner of a control switch, has an OFF, an operating and an ON position and is connected to the control relay and to a switchable, live line. In the OFF position or when the switchable line is not energized, the control relay is deactivated to provide a small hydraulic fluid flow. Thereafter, to set the control relay in its activated position and to provide a high hydraulic fluid flow, the selector must first be brought to its first ON position before being released to the operating position.

Such a control device is relatively simple and inexpensive and prevents operation of a transmission or a vehicle at the start of work or generally after deactivating the power supply in an unintended operating state or in a high-speed region, even if the selection device is in a position for a further operating state or for a high-speed operation. Elaborate and expensive interlocking links or circuits are not needed and the device operates simply and directly.

Fig. 1

eine schematische Darstellung einer Steuerungseinrichtung zur Verwendung an einem Fahrzeug mit einem Bereichsauswahlventil zur Auswahl eines Geschwindigkeitsbereichs und

Fig. 2

eine schematische Darstellung eines ähnlichen Hydrauliksystems mit einem Bereichsauswahlventil für unterschiedliche Durchflußbereiche.

In the drawing, an embodiment of the invention described in more detail below is shown. It shows:

Fig. 1

a schematic representation of a control device for use on a vehicle with an area selection valve for selecting a speed range and

Fig. 2

a schematic representation of a similar hydraulic system with a range selector valve for different flow ranges.

Referring now to Fig. 1, there is shown a speed control system 10 for controlling a hydraulic transmission 12 having a high-speed output operation and a low-speed output operation to drive a vehicle 14 such as a skid steer loader) in two or more speed ranges. A range selector valve 16, embodied as an electrohydraulic transmission speed control valve, provides the high speed range of operation when activated and the low speed range of the transmission when deactivated

In order to control the speed range, a speed range selector 20 and a speed control relay, hereinafter referred to as the control relay 22, are interposed between a switchable live line 24 and a control input 26 of the range selector valve 16. The selection device 20 has inputs 30, which are connected to one another via a line 31 and to a switchable output 32 on the control relay 22. An opposite output 34 of the control relay 22 is connected to the switchable line 24. The inputs 30 are also connected to a control input or terminal 42 of the coil of the control relay 22. The opposite terminal 44 of the coil is grounded.

The selector 20, as shown in Fig. 1, has a first or low speed position (the upper position in the illustration) in which an output 48 connected to the line to the terminal 42 is open, so that the Area selection valve 16 no current is applied and the Low speed range of operation is provided. In the first position, a second output 50 is connected via the switch to the line 31 to provide a closed path between the switchable line 24 and the control input and the terminal 42 of the control relay 22 available. Therefore, when the switchable line 24 is energized and the selector 20 is in its first or low speed position, as shown in FIG. 1, the holding relay 22 will activate to provide a closed path between the outputs 32 and 34 and connect the switchable line 24 to the terminal 42, so that the relay is kept in the ON position (bootstrapped), as long as the switchable line 24 is energized. However, if the path to the control input 26 is open when the selector 20 is in its shown first or low speed position, the range selector valve 16 will be deactivated and the low speed range will be established by the range selector valve 16. To invoke high-speed operation, an operator moves the selector 20 downwardly from the position shown in FIG. 1 to form a closed loop from the control input 26 to the live, switchable line 24 via the outputs 48 and 30 of the selector 20 and the outputs 32 and 34 of the control relay 22 to justify. The range selection valve 16 is activated for high-speed operation.

If the switchable line 24 does not become live for some reason, the control relay 22 will deactivate and open the circuit between the switchable line 24 and the area selection valve 16. When the switchable line 24 becomes energized again, the control relay 22 may be (bootstrapped) only in its activated position when the selector 20 has first been in its low speed position. Therefore, when an operator turns on the selector 20 in its high-speed position, the control relay 22 becomes leaves, when the switchable line 24 is energized, not be activated before the selector 20 is first brought up to its low speed position to supply the output 42 via the outputs 30 and 50. The system is forced to operate in the low speed condition until the operator moves the selector 20 upon energization of the switchable line 24, thereby preventing an initial, unintended, high speed operation. A diode 56 is connected in parallel with the solenoid of the range selector valve 16 to limit voltage spikes.

As shown in FIG. 1, the switchable line 24 is connected to a conventional ignition switch 60 of the vehicle 14. The ignition switch 60 has an off (shown), an operating and a start position and comprises a connected to the switchable line 24 terminal 62. When the ignition switch 60 in its second or operating position (or in an additional position when an additional position on the Switch is provided), system power is supplied to the switchable line 24 via the terminal 62 and an output 64, which is connected to a power source, such as a battery or an alternator, of the vehicle 14. When the ignition switch 60 is in its off or in its starting position, the switchable line 24 is not energized. Therefore, when the vehicle 14 is started or when the ignition switch 60 is in its display, the control relay 22 is deactivated. In turn, when the switchable lead 24 becomes energized by movement of the ignition switch 60 to its operative (or auxiliary) position, the selector 20 must first be brought into its low speed position (shown) to activate the control relay 22 and to provide high speed selection Select device 20 to allow.

Referring now to FIG. 2, a hydraulic control system 70 is shown to selectively apply hydraulic lines or auxiliary lines 72 to a hydraulic system 74 of the vehicle 14. A common source of hydraulic fluid (not shown) is connected via a high flow, electro-hydraulic, low flow control valve, hereinafter referred to as range selector valve 76. A three position flow control switch or selector 80 has an OFF position (shown), a central operating position and a lower activation position. A port 84 is connected to an input control line 86 of the range selector valve 76. A second port 90 is connected to a source of control power on the vehicle 14, such as the switchable line 24 from the ignition switch 60. An output 92 is connected to the contacts of the selector 80 so that an open circuit is provided to the output 92 when the selector 80 is in its OFF position, that the output 84 is connected to the output 92 when the Selector 80 is in its operating position and that a connection between the terminals 84 and 90 is made when the selector 80 is in its activation position.

A high flow relay or control relay 100 has a control input 102 which is connected to the output 92 of the selector 80, and an opposite terminal 104 which is grounded. A switchable relay terminal 112 is connected to the control line 86 of the control valve 76 and to the output 84. The opposite terminal 114 is connected to a switchable line 116, which has a current-carrying and a non-current-carrying state. As can be seen from Fig. 2, when the control relay 100 is deactivated, the control relay 100 can only be activated by the selector 80 in its lowest position or Activation position is brought while the output 90 is energized (for example, while the ignition switch 60 is in its on or additional position) to build a closed circuit between the outputs 90 and 92 and to supply power to the solenoid of the control relay 100. The control relay 100 will activate and establish a closed loop between the switchable line 116 and the control input 102 via the terminals 114, 112 and 84, 92. When the switchable lead 116 becomes energized, the retaining relay 100 is bootstrapped in its ON position when the selector 80 is in its operative or activated position and the range selector valve 76 is activated to provide a high flow condition to the auxiliary leads 72 to deliver. When the operator releases the selector 80, the selector 80 moves to its operative position.

If, for some reason, the line does not become live, the control relay 100 will be deactivated and the control valve 76 will return to its low flow condition. The control relay 100 can then only be reactivated by the selector 80 is manually brought into the activation position when the output 90 is applied. This prevents inadvertent starting of the system in the high flow state. A backlight 130 illuminates the switch area when the output 90 is energized. A second signal light 132 is connected between the output 92 and ground and provides a signal to the operator when the control relay 100 is energized.

With the description of the preferred embodiment, it will be apparent that various modifications can be made without departing from the scope of the invention as defined by the appended claims.

Claims (6)

1. Control assembly (10) comprising a selection device (20, 80) which may be connected to a power source via a switchable line (24) and has at least a first position and a second position, said assembly also comprising a range selection valve (16, 76) which may be electrically actuated by the selection device (20, 80) and makes available at least a first and a second operating range, the first operating range being a low-speed range and the second operating range being a high-speed range of a gear mechanism, characterised in that the selection device (20, 80) is so connected to a control relay (22, 100) that, when the selection device (20, 80) assumes its first position and the switchable line (24) carries current, the control relay (22, 100) closes a connection which is open if the switchable line (24) is current-free and which connects the range selection valve (16, 76) and the control relay (22, 100) to the power source or the switchable line (24) when the selection device (20, 80) assumes its second position.
2. Control assembly according to claim 1 of the preceding claims, characterised in that the selection device (20, 80) has a first output terminal (48, 84) which may be connected to the range selection valve (16, 76), and a second output terminal (50, 90) which may be connected to the switchable line (24).
3. Control assembly according to one or more of the preceding claims, [characterised] in that the control relay (22, 100) has a solenoid as well as a switch controlled by same.
4. Control assembly according to one or more of the preceding claims, characterised in that at least the switchable line (24) is connected to an ignition switch (60) and/or carries current when the ignition switch (60) is in a starting or operating position.
5. Control assembly according to one or more of the preceding claims, characterised in that the first operating range is a low flow range for hydraulic fluid and the second operating range is a high flow range for hydraulic fluid.
6. Vehicle (14), especially a utility vehicle, which has a control assembly (10) according to one or more of the preceding claims.

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